Search found 138 matches

by mdwmark
Tue Jul 07, 2020 6:19 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader Coronagraph
Replies: 18
Views: 514

Re: Baader Coronagraph

That sounds like your talking about only the bandpass part of the filter. If you make an bandpass at Ha , it will turn back on in the green, and be full on in the blue end of the spectrum. On the long side it will start back on around 780nm. The bandpass normally used were 5 Ang two cavity and block...
by mdwmark
Wed Jun 10, 2020 6:48 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Daystar Scout 60 Image Problem
Replies: 4
Views: 325

Re: Daystar Scout 60 Image Problem

A solid etalon doesn't de-contact. That is something else.
Mark W.
by mdwmark
Wed Jun 10, 2020 6:34 am
Forum: This is SolarChat !!
Topic: AR 2765 and the long filament - June 7, 2020
Replies: 26
Views: 532

Re: AR 2765 and the long filament - June 7, 2020

Hi Ffellah, Your image is in the red wing( +.5Ang). That is a good example of what the red wing looks like. I would drop the temperature 2 or 3 deg first and see the difference. When you are in the center of the Ha line, it will have a softer look. The tips of the photosphere will have less contrast...
by mdwmark
Fri Jun 05, 2020 9:29 pm
Forum: This is SolarChat !!
Topic: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31
Replies: 27
Views: 571

Re: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31

Hi Chrisitian, I was not concerned with your project, I really like your idea using it with the uncoated mirror. It's the people that would put it on an normal scope without dropping the transmission that I worry about. That is my business, making safe solar filters. You would be surprise to see how...
by mdwmark
Fri Jun 05, 2020 7:07 am
Forum: This is SolarChat !!
Topic: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31
Replies: 27
Views: 571

Re: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31

By using them in tandem , the 3 cavity will clean up the side bands of the single cavity filter even thou it is broader. This will give you better contrast. The main problem with these very narrow bandpasses is that they have trouble with edge to edge uniformity, usually on one axis. I would think t...
by mdwmark
Thu Jun 04, 2020 7:07 am
Forum: This is SolarChat !!
Topic: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31
Replies: 27
Views: 571

Re: Fun with Ca K filters. First light of Alluxa Ca K filter, May 31

narrower is not necessarily better. Christian's filter is a 3 cavity design. This means that it might be broader at the HW. But more of the K-line will stay inside the bandpass. If you look at a single cavity filter, first at 1% they are about 10X the Hw. An 3 cavity filter is only 2X the Hw at that...
by mdwmark
Tue Mar 31, 2020 6:10 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: SolarMax 3 BF Questions (Help)
Replies: 12
Views: 4000

Re: SolarMax 3 BF Questions (Help)

The 6Ang filter is just a bandpass. So it will have the bandpass at Ha but will turn back on at about 500nm and 780nm. The bandpass will look the same even when it fails. If you are looking at the color. The most common is the wavelength will shift either long or short over time. This will make the ...
by mdwmark
Fri Nov 15, 2019 5:38 am
Forum: Solar Scope Modifications
Topic: PST mod on a C14
Replies: 11
Views: 3008

Re: PST mod on a C14

OK George is right. You will need to tilt the etalon 1.8deg to reline the etalon to the off axis. The tilt will need to line up with you ERF. So it the ERF is at 12 o'clock. The etalon will be tilted backwards at 12 o'clock. This is the same that we have been doing from the 80's with mica filters. A...
by mdwmark
Wed Sep 11, 2019 7:58 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Blocking filters and wintertime
Replies: 20
Views: 5827

Re: Blocking filters and wintertime

The temperature of the blocker is important. You need to match it up with the etalon so that it will block the next peaks. Air spaced etalons use an blocker that is 6-8Ang at the HW. If they are at 6563Ang at 23C for the CW. Then when it is 43C the CW has moved to 6566.3Ang into the red. So Now you ...
by mdwmark
Fri Aug 09, 2019 4:39 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: it seems that my Quark is not reaching the working temperature
Replies: 13
Views: 3171

Re: it seems that my Quark is not reaching the working temperature

You have a few thing going on that you need to look at. 1) at F/21 the center wavelength has shifted blue( same as tilting the filter). The HW is also broaden out to about 1.3Ang if you started at .7Ang. 2) your using a yellow ERF, so you will be getting a lot more heat into the scope then if you us...
by mdwmark
Sun Feb 10, 2019 2:21 am
Forum: This is SolarChat !!
Topic: Old Coronado BF30
Replies: 27
Views: 3025

Re: Old Coronado BF30

Or not, If that is just a blocker. Then it will turn back on at 750nm in the red. KG3 is down at about 1000nm. So that area between 750 and 1000nm will be leaking energy. That will be enough to be a problem(not to good for your eye). The short side, RG630 will block anything there. If it is really a...
by mdwmark
Sat Dec 01, 2018 1:20 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

Gordon Garcia, That's a name from the past. I haven't talk to him in years. I hope he is still around. He did some great stuff with film. SO-410, I wonder how many remember that film. Kodak changed the name later, but I don't remember what it was. Using the tilt for fine adjustment is what I had in ...
by mdwmark
Fri Nov 30, 2018 4:28 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: anyone tried one of these yet - Quark Mg
Replies: 8
Views: 2965

Re: anyone tried one of these yet - Quark Mg

I was not happy with the one they brought to the Big Bear convention. It had a strong secondary reflection. (double solar image). But they seem to be happy with it.
Mark
by mdwmark
Fri Nov 30, 2018 4:14 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

Ha Ha ha, That's the old TS-2 housing. I came up with that for the etalons that run around 30-40C(the ATM worked poorly there). Del quit using them when I left. They where larger so that a standard rubber strip heater would fit inside. They must have been with the stuff when the new Daystar took ove...
by mdwmark
Mon Nov 26, 2018 11:27 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: That orange PST Rust / A Fungus?
Replies: 4
Views: 2259

Re: That orange PST Rust / A Fungus?

that looks like normal failure
Mark W.
by mdwmark
Mon Nov 19, 2018 1:21 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Rust on either Lunt or Coronado
Replies: 7
Views: 3084

Re: Rust on either Lunt or Coronado

That's not a humidity problem on the images. Humidity usually fails from the outside in. This is something different.
Mark W.
by mdwmark
Fri Nov 16, 2018 8:15 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

HI Ken, The normal screw was a plastic knurled-head thumb screw.We would smooth the bottom of the screw so it would not dig into the cell of the filter stack. The easiest way to check the filter. Is to put on the scope, point it at the sun, and without an eyepiece look into the back(red side). Be ba...
by mdwmark
Thu Nov 15, 2018 11:38 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

Hi Ken,
The screw is a 10/32 thread. If you have to change the threads to metric, Take off the back plate with the spring. You should have enough room to run a tap with the cell tilted.
Mark W.
by mdwmark
Wed Nov 14, 2018 8:28 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

HI group, The cost of converting the TS-1 to TEC is not that much. But I like to check them out first to make sure the etalon is still good. If you are in Europe they will be ship through Baader Planetarium. So you can contact them about shipping. In the US they would go through Alpine Astro. The bl...
by mdwmark
Thu Nov 08, 2018 7:57 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar T scanner TS-1??
Replies: 18
Views: 5200

Re: DayStar T scanner TS-1??

Well I know of a few that are used. I converted them to a TEC controlled ovens so they will work all year long.
Mark
by mdwmark
Wed Oct 10, 2018 5:53 am
Forum: Solar Scope Modifications
Topic: Pst Cak filter secret -
Replies: 10
Views: 3738

Re: Pst Cak filter secret -

Hi Apollo, Just checking , the GG395 and the KG3 are these hard coated of soft coated? If they are soft coated, then they will need to be used in the back of the telescope. Soft coating filters with that many layers would never come out 1/4 wave on transmission. On the KG3 , the SiO2 overcoat , is t...
by mdwmark
Sat Oct 06, 2018 5:06 am
Forum: Solar Scope Modifications
Topic: Pst Cak filter secret -
Replies: 10
Views: 3738

Re: Pst Cak filter secret - Vengeance against chroma

There prices are right in line with everyone else. That $825 for a two cavity(I would think 2 cavity would do better then OD2) at 1 piece is a good deal. Your idea about how easy it is to make a filter may be true for an AR's or edge filter or something like a 10-20nm HW bandpass. But a ultra narrow...
by mdwmark
Sun Sep 30, 2018 6:03 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 117
Views: 25412

Re: Narrowest 393.37 ever by Apollo Lasky

Hi Group, OK Christian, I modeled an filter similar to the Chroma. My design came out 1.2Ang which I though was close enough. CW Ang HW Ang %of original transmission at zero deg 3934 1.2 100 At F/30 3933.79 1.23 96 at F/20 3933.54 1.28 86 at F/15 3933.30 1.7 70 at F/10 3932,3 3.2 40 at F/8 3931.7 4....
by mdwmark
Wed Sep 05, 2018 8:30 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 117
Views: 25412

Re: 393.4 bp0.1 - yes it does exist.

Hi Bob, the only reason I can think of why the .1nm filters has a lower contrast then the PST is that it is not fully blocked. Or it is not on band. There may be a leak in the long side blocking. It is not uncommon to have a blue/green leak that would drop the contrast of the image. Are you using a ...